Imaging sensor, imaging apparatus, electronic device, and imaging method with photoelectric conversion elements having different exposure times

ABSTRACT

There is provided an image sensor including at least three pixel transfer control signal lines, on a per line basis, configured to control exposure start and end timings of a pixel in order for exposure timings of a plurality of the pixels constituting one line in a specific direction to have at least three patterns.

CROSS REFERENCES TO RELATED APPLICATIONS

This is a Continuation Application of U.S. patent application Ser. No.13/722,463, filed Dec. 20, 2012, to be issued as U.S. Pat. No. 8,908,076on Dec. 9, 2014, which in turn claims priority from Japanese ApplicationNo.: 2012-003997, filed on Jan. 12, 2012, the entire contents of whichare incorporated herein by reference.

BACKGROUND

The present technology relates to an image sensor. More particularly,the present technology relates to an image sensor that reads from aplurality of pixels at a plurality of exposure timings, an imagingapparatus and electronic device having the image sensor, and an imagingmethod for use in the image sensor, the imaging apparatus and theelectronic device.

Recently, electronic device (for example, an imaging apparatus such as adigital still camera) that generates an image (image data) by imaging anobject such as a human and records the generated image (image data) asimage content (an image file) has become widespread. As an image sensorfor use in the electronic device, a charge coupled device (CCD) sensor,a complementary metal oxide semiconductor (CMOS) sensor, and the likehave become widespread.

For example, an image sensor in which a pixel for generating along-time-exposure image and a pixel for generating ashort-time-exposure image are arranged adjacent to each other on animaging surface has been proposed (for example, see Japanese PatentApplication Publication No. 2010-62785).

SUMMARY

A high-dynamic-range image of which camera blur has been appropriatelycorrected can be generated in the above-described related art.

As described above, in the above-described related art, theappropriately corrected image can be generated. However, pixel sizereduction has recently progressed. Thus, it is important to performappropriate imaging control to cope with the pixel size reduction andgenerate an appropriate image corresponding to the pixel size reduction.

It is desirable to perform appropriate imaging control.

The present technology is provided to solve the above-mentioned issues.According to a first embodiment of the present technology, there isprovided an image sensor and an imaging method thereof including atleast three pixel transfer control signal lines configured to controlexposure start and end timings of each pixel on a per line basis so thatexposure timings of a plurality of pixels constituting one line in aspecific direction have at least three patterns. Thereby, there is aneffect that the exposure timings of the plurality of pixels constitutingthe one line in the specific direction have the at least three patternsby controlling the exposure start and end timings of each pixel.

Further, according to the first embodiment of the present technology, Afirst line on which a pixel of first spectral sensitivity and a pixel ofsecond spectral sensitivity constituting the plurality of pixels arealternately arranged in the specific direction and a second line onwhich a pixel of the first spectral sensitivity and a pixel of thirdspectral sensitivity constituting the plurality of pixels arealternately arranged in the specific direction may be alternatelyarranged in an orthogonal direction orthogonal to the specificdirection. Thereby, there is an effect that the exposure timings of theplurality of pixels constituting the one line in the specific directionhave the at least three patterns in the image sensor in which the firstand second lines are alternately arranged in the orthogonal direction.

Further, according to the first embodiment of the present technology,using at least two pixel transfer control signal lines of the pixeltransfer control signal lines in the first line, some pixelsconstituting the first line may be designated as first pixels forgenerating a long-time-exposure image according to continuous exposurewithin a predetermined period, and the other pixels constituting thefirst line may be designated as second pixels for generating a pluralityof short-time-exposure images according to intermittent exposure withinthe predetermined period. Using at least two pixel transfer controlsignals of the pixel transfer control signal lines in the second line,some pixels constituting the second line may be designated as the firstpixels and the other pixels constituting the second line may bedesignated as the second pixels. Thereby, there is an effect that somepixels constituting the first line are designated as the first pixelsand the other pixels constituting the first line are designated as thesecond pixels using the at least two pixel transfer control signal linesin the first line, and some pixels constituting the second line aredesignated as the first pixels and the other pixels constituting thesecond line are designated as the second pixels using the at least twopixel transfer control signal lines in the second line.

Further, according to the first embodiment of the present technology,using the pixel transfer control signal lines, a first pixel group inwhich a predetermined number of pixels in the specific direction and apredetermined number of pixels in the orthogonal direction are connectedstepwise is designated as the first pixels, a second pixel group inwhich a predetermined number of pixels in the specific direction and apredetermined number of pixels in the orthogonal direction are connectedstepwise is designated as the second pixels, and the first pixel groupand the second pixel group may be alternately arranged in the specificdirection. Thereby, there is an effect that the first pixel group andthe second pixel group are alternately arranged in the specificdirection.

Further, according to the first embodiment of the present technology, inthe one line, using at least two pixel transfer control signal lines ofthe pixel transfer control signal lines, an exposure period of the pixelof the first spectral sensitivity constituting the first pixels may beset to be shorter than an exposure period of the pixel of the second orthird spectral sensitivity constituting the first pixels. Thereby, thereis an effect that the exposure period of the pixel of the first spectralsensitivity constituting the first pixels is set to be shorter than theexposure period of the pixel of the second or third spectral sensitivityconstituting the first pixels using the at least two pixel transfercontrol signal lines in the one line.

Further, according to the first embodiment of the present technology, inthe one line, using at least two pixel transfer control signal lines ofthe pixel transfer control signal lines, an exposure period of the pixelof the first spectral sensitivity constituting the second pixels may beset to be shorter than an exposure period of the pixel of the second orthird spectral sensitivity constituting the second pixels. Thereby,there is an effect that the exposure period of the pixel of the firstspectral sensitivity constituting the second pixels is set to be shorterthan the exposure period of the pixel of the second or third spectralsensitivity constituting the second pixels using the at least two pixeltransfer control signal lines in the one line.

Further, according to the first embodiment of the present technology, anarrangement of the pixel of the first spectral sensitivity, the pixel ofthe second spectral sensitivity, and the pixel of the third spectralsensitivity may be a Bayer arrangement. Thereby, there is an effect thatthe exposure timings of the plurality of pixels constituting the oneline in the specific direction have the at least three patterns bycontrolling the exposure start and end timings of each pixel in theBayer arrangement.

Further, according to the first embodiment of the present technology, byperforming addition on the same type of pixels in units of lines in theorthogonal direction on pixels constituting two first lines adjacent inthe orthogonal direction and performing addition on the same type ofpixels in units of lines of the orthogonal direction on pixelsconstituting two second lines adjacent in the orthogonal direction, anarrangement of pixel signals after the addition may be a Bayerarrangement. Thereby, there is an effect that, by performing theaddition on the same type of pixels in units of lines of the orthogonaldirection for the pixels constituting the two first lines adjacent inthe orthogonal direction and performing the addition on the same type ofpixels in units of lines of the orthogonal direction for the pixelsconstituting the two second lines adjacent in the orthogonal direction,the arrangement of the pixel signals after the addition has the Bayerarrangement.

Further, according to the first embodiment of the present technology, inthe one line, at least one pixel transfer control signal line isconnected to the pixel of the first spectral sensitivity constitutingthe plurality of pixels and at least two pixel transfer control signallines may be connected to the pixel of the second or third spectralsensitivity constituting the plurality of pixels. Thereby, there is aneffect that the image sensor having the at least one pixel transfercontrol signal line connected to the pixel of the first spectralsensitivity constituting the plurality of pixels in the one line and theat least two pixel transfer control signal lines connected to the pixelof the second or third spectral sensitivity constituting the pluralityof pixels is used.

Further, according to the first embodiment of the present technology,the at least one pixel transfer control signal line connected to thepixel of the first spectral sensitivity may be arranged between the atleast two pixel transfer control signal lines connected to the pixel ofthe second or third spectral sensitivity. Thereby, there is an effectthat the image sensor in which the at least one pixel transfer controlsignal line connected to the pixel of the first spectral sensitivity isarranged between the at least two pixel transfer control signal linesconnected to the pixel of the second or third spectral sensitivity isused.

Further, according to the first embodiment of the present technology,the pixel of the first spectral sensitivity may be a green (G) pixel,the pixel of the second spectral sensitivity may be a red (R) pixel, andthe pixel of the third spectral sensitivity may be a blue (B) pixel.Thereby, there is an effect that an image sensor formed by green (G),red (R), and blue (B) pixels is used.

Further, according to the first embodiment of the present technology,the plurality of pixels may share one analog/digital (A/D) converterbetween two adjacent pixels in the specific direction. And exposuretimings of the two adjacent pixels may be shifted using at least twopixel transfer control signal lines of the pixel transfer control signallines. Thereby, there is an effect that the exposure timings of the twoadjacent pixels are shifted using the at least two pixel transfercontrol signal lines.

Further, according to the first embodiment of the present technology, apixel group formed by a plurality of pixels in the specific directionand a plurality of pixels in an orthogonal direction may share onefloating diffusion. Thereby, there is an effect that the pixel groupformed by the plurality of pixels in the specific direction and theplurality of pixels in the orthogonal direction shares the one floatingdiffusion (FD).

Further, according to a second embodiment, there is provided an imagingapparatus and an imaging method thereof including an image sensorconfigured to have at least three pixel transfer control signal linesfor controlling exposure start and end timings of each pixel on a perline basis so that exposure timings of a plurality of pixelsconstituting one line in a specific direction have at least threepatterns, and an image processing section configured to perform imageprocessing on an image signal output from the image sensor. Thereby,there is an effect that the image processing on the image signal outputfrom the image sensor in which the exposure timings of the plurality ofpixels constituting the one line in the specific direction have the atleast three patterns is performed by controlling the exposure start andend timings of each pixel.

Further, according to a third embodiment, there is provided electronicdevice and an imaging method thereof including an image sensorconfigured to have at least three pixel transfer control signal linesfor controlling exposure start and end timings of each pixel on a perline basis so that exposure timings of a plurality of pixelsconstituting one line in a specific direction have at least threepatterns, and an image processing section configured to perform imageprocessing on an image signal output from the image sensor, and acontrol section configured to control the image signal subjected to theimage processing to be output or recorded. Thereby, there is an effectthat the image processing on the image signal output from the imagesensor in which the exposure timings of the plurality of pixelsconstituting the one line in the specific direction have the at leastthree patterns is performed by controlling the exposure start and endtimings of each pixel and the image signal is controlled to be output orrecorded.

In accordance with the embodiments of the present technology, there isan excellent effect that appropriate imaging control can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

FIG. 1 is a diagram illustrating an example of a pixel arrangement ofcolor filters (CFs) mounted on a light receiving section of an imagesensor 100 in accordance with a first embodiment of the presenttechnology;

FIG. 2 is a diagram illustrating a configuration example of a basiccircuit of a pixel 10 provided in the image sensor 100 in accordancewith the first embodiment of the present technology;

FIG. 3 is a diagram illustrating a configuration example of a pixelcontrol circuit and a pixel wiring of the image sensor 100 in accordancewith the first embodiment of the present technology;

FIG. 4 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology;

FIG. 5 is a diagram illustrating an example of the pixel arrangement ofthe CFs mounted on the light receiving section of the image sensor 100in accordance with the first embodiment of the present technology;

FIG. 6 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology;

FIG. 7 is a diagram illustrating an example of the pixel arrangement ofthe CFs mounted on the light receiving section of the image sensor 100in accordance with the first embodiment of the present technology;

FIG. 8 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology;

FIG. 9 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology;

FIG. 10 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology;

FIG. 11 is a diagram illustrating a configuration example of a pixelcontrol circuit and a pixel wiring of an image sensor 300 in accordancewith a second embodiment of the present technology;

FIG. 12 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 300 in accordance with the secondembodiment of the present technology;

FIG. 13 is a diagram illustrating an example of a pixel arrangement ofCFs mounted on a light receiving section of an image sensor 500 inaccordance with a third embodiment of the present technology;

FIG. 14 is a diagram illustrating an output example after pixel additionperformed on pixels constituting the image sensor 500 in accordance withthe third embodiment of the present technology;

FIG. 15 is a diagram illustrating a configuration example of a basiccircuit of a pixel provided in the image sensor 500 in accordance withthe third embodiment of the present technology;

FIG. 16 is a diagram illustrating a configuration example of a pixelcontrol circuit and a pixel wiring of the image sensor 500 in accordancewith the third embodiment of the present technology;

FIG. 17 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 500 in accordance with the thirdembodiment of the present technology;

FIG. 18 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 500 in accordance with the thirdembodiment of the present technology;

FIG. 19 is a diagram illustrating a configuration example of a basiccircuit of a pixel provided in an image sensor 700 in accordance with afourth embodiment of the present technology;

FIG. 20 is a diagram illustrating a configuration example of a pixelcontrol circuit and a pixel wiring of the image sensor 700 in accordancewith the fourth embodiment of the present technology;

FIG. 21 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 700 in accordance with the fourthembodiment of the present technology;

FIG. 22 is a diagram schematically illustrating a layout example ofpixels and pixel transfer control signal lines constituting an imagesensor in accordance with a fifth embodiment of the present technology;and

FIG. 23 is a block diagram illustrating a functional configurationexample of an imaging apparatus 800 in accordance with an embodiment ofthe present technology.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Hereinafter, modes (hereinafter referred to as embodiments) for carryingout the present technology will be described. Description will be givenin the following order.

1. First Embodiment (Example in Which Three Pixel Transfer ControlSignal Lines Are Provided on One Line in Horizontal Direction)

2. Second Embodiment (Example of Image sensor in Which Two Pixels inVertical Direction Share One A/D Converter)

3. Third Embodiment (Example of Image sensor in Which Signals Read fromPixels Are Added and Used)

4. Fourth Embodiment (Example of Image sensor Using Pixel Circuit Sharedby Eight Pixels)

5. Fifth Embodiment (Layout Example of Pixel Transfer Control SignalLines)

6. Application Example

<1. First Embodiment>

[Pixel Arrangement Example of CFs]

FIG. 1 is a diagram illustrating an example of a pixel arrangement ofCFs mounted on a light receiving section of an image sensor 100 inaccordance with the first embodiment of the present technology. In FIG.1, each rectangle schematically represents a pixel.

In addition, in the first embodiment of the present technology, anexample of CFs with three colors of RGB including G, R, and B is shown.Here, rectangles that are not hatched with diagonal lines representlong-time-exposure pixels, and rectangles that are hatched with diagonallines represent short-time-exposure pixels.

Here, a long-time-exposure pixel is a pixel to be read by continuousexposure (long-time exposure) within a predetermined exposure period. Inaddition, a short-time-exposure pixel is a pixel for which intermittentexposure (short-time exposure) is performed within a predeterminedexposure period and from which reading is performed at each exposuretime.

In addition, a reference sign inside each rectangle indicates a type ofCF. For example, among G pixels, “G_(L)” is assigned to along-time-exposure pixel and “G_(S)” is assigned to ashort-time-exposure pixel. In addition, among R pixels, “R_(L)” isassigned to a long-time-exposure pixel and “R_(S)” is assigned to ashort-time-exposure pixel. Further, among B pixels, “B_(L)” is assignedto a long-time-exposure pixel and “B_(S)” is assigned to ashort-time-exposure pixel.

As described above, in the image sensor 100, a first pixel group(short-time-exposure pixel group) and a second pixel group(long-time-exposure pixel group) are alternately arranged in ahorizontal direction. Here, the first pixel group (short-time-exposurepixel group) is a pixel group in which three first pixels(short-time-exposure pixels) arranged adjacent to one another in thehorizontal direction are connected stepwise to three first pixels(short-time-exposure pixels) arranged adjacent to one another in avertical direction. That is, the first pixel group (short-time-exposurepixel group) is a pixel group formed by rectangles hatched with diagonallines. In addition, the second pixel group (long-time-exposure pixelgroup) is a pixel group in which three second pixels (long-time-exposurepixels) arranged adjacent to one another in the horizontal direction areconnected stepwise to three second pixels (long-time-exposure pixels)arranged adjacent to one another in the vertical direction. That is, thesecond pixel group (long-time-exposure pixel group) is a pixel groupformed by rectangles not hatched with diagonal lines. In the firstembodiment of the present technology, a configuration illustrated inFIG. 1 will be described to be a spatially varying exposure (SVE) zigzagsensitivity pattern. In imaging within one frame, the imaging isnormally performed on all pixels in the same exposure period. On theother hand, the SVE is an imaging method of performing imaging whileperiodically changing an exposure period within one frame in imagingwithin one frame and implementing the effect of a wide dynamic range orthe like using signal processing technology.

In addition, in the image sensor 100, an arrangement of a pixel (forexample, a G pixel) of first spectral sensitivity, a pixel (for example,an R pixel) of second spectral sensitivity, and a pixel (for example, aB pixel) of third spectral sensitivity becomes a Bayer arrangement.

As described above, the first embodiment of the present technology isaimed at implementing a pixel sensitivity pattern of two types ofsensitivities within one frame on a CMOS image sensor (CIS). Forexample, it is possible to change the sensitivity, for example, bysetting a pixel exposure period as a different exposure period.

[Configuration Example of Basic Circuit of Pixel]

FIG. 2 is a diagram illustrating the configuration example of the basiccircuit of a pixel 10 provided in the image sensor 100 in accordancewith the first embodiment of the present technology. In FIG. 2, aconfiguration example of a CIS pixel circuit of a general configurationof four transistors (Tr) that are not shared by pixels is illustrated.

The pixel 10 is formed by a photodiode (PD) 11, which is a lightreceiving section, an FD 12, and four MOS-field effect transistors(MOSFETs) (M1 to M4) 21 to 24. In addition, the pixel 10 is connected toa pixel transfer control signal line (pixel transfer gate control signalline) (TRG) 31, a pixel read selection control signal line (SEL) 32, avertical signal line (read line) (VSL) 33, and a pixel reset controlsignal line (RST) 34.

Light with which a pixel is irradiated is converted into electrons inthe PD 11, and charges corresponding to an amount of light areaccumulated in the PD 11. The MOSFET (M1) 21 controls a charge transferbetween the PD 11 and the FD 12. A signal of the pixel transfer controlsignal line (TRG) 31 is applied to a gate electrode of the MOSFET (M1)21, and hence the charges accumulated in the PD 11 are transferred tothe FD 12. The FD 12 is connected to a gate electrode of the MOSFET (M3)23. When a control signal of the pixel read selection control signalline (SEL) 32 is applied to a gate electrode of the MOSFET (M4) 24, avoltage corresponding to the charges accumulated in the FD 12 can beread as a signal from the vertical signal line (VSL) 33. When a resetsignal of the pixel reset control signal line (RST) 34 is applied to agate electrode of an MOSFET (M2) 22, a charge accumulation state isreset because the charges accumulated in the FD 12 flow through theMOSFET (M2) 22.

[Configuration Example of Pixel Control Circuit and Pixel Wiring]

FIG. 3 is a diagram illustrating the configuration example of the pixelcontrol circuit and the pixel wiring of the image sensor 100 inaccordance with the first embodiment of the present technology.

The image sensor 100 includes a vertical scanning control circuit 110, ahorizontal transfer circuit 120, analog/digital (A/D) converters 131 to138, memories 141 to 148, and a plurality of pixels (pixels R1 to B48).The plurality of pixels (pixels R1 to B48) each having the structureillustrated in FIG. 2 are arranged in a two-dimensional (2D) squarelattice in the image sensor 100. In addition, CF types R, G, and B andidentification numbers 1 to 48 are assigned inside rectanglesrepresenting pixels.

In general, a sequence of a longitudinal direction of the image sensoris referred to as a column and a sequence of a lateral direction isreferred to as a row. Thus, hereinafter, description will be givenappropriately using names of the column and the row. In addition, inthis example, some pixels (the pixels R1 to B48) in the image sensor 100and sections associated therewith are representatively shown, and theillustration and description of the other configurations are omitted.

The vertical scanning control circuit 110 turns on/off a switch betweeneach pixel and the vertical signal line VSL by controlling signal linesRST, TRG, and SEL wired in a row direction. Control of the signal lineswill be described in detail with reference to FIGS. 4, 6, 8 to 10 andthe like.

The horizontal transfer circuit 120 is a circuit for horizontallytransferring digital data held in the memories 141 to 148.

Each of the A/D converters 131 to 138 converts image data, which is ananalog value, from each pixel into digital data (a digital value).

The memories 141 to 148 sequentially store digital data converted by theA/D converters 131 to 138.

In addition, vertical signal lines (read lines) (VSL) 151 to 158 arewired in a vertical column direction, and pixels on the same verticalcolumn share one read line. In addition, the vertical signal lines (VSL)151 to 158 are exclusively connected to an output terminal 121 by thehorizontal transfer circuit 120. Here, pixels R1 and G2 and the like(pixels with the subscript “L” assigned to pixels illustrated in FIG. 1)are pixels (long-time-exposure pixels) that are continuously exposed tolight within a predetermined exposure period (long-time exposure) andultimately read. In addition, pixels R3 and R7 and the like (pixels withthe subscript “S” assigned to pixels illustrated in FIG. 1) are pixels(short-time-exposure pixels) that are intermittently exposed to lightwithin a predetermined exposure period (short-time exposure) and read ateach exposure time.

As described above, one certain pixel can be connected to the outputterminal 121 according to selection control of the vertical scanningcontrol circuit 110. Thus, signals of all pixels can be read in timedivision while the pixels are sequentially selected.

In addition, for lines in the horizontal direction in the image sensor100, pixel transfer control signal lines (TRG) 162, 163, and the like, apixel read selection control signal line (SEL) 165 and the like, and apixel reset control signal line (RST) 161 and the like are wired. Inaddition, in accordance with the SVE zigzag sensitivity pattern, the Ror B pixel is connected to the pixel transfer control signal line (TRG)at every other color pixel.

Here, pixel transfer control signal lines TRG in one line in thehorizontal direction for implementing the sensitivity patternillustrated in FIG. 1 will be described. For example, in terms of thehorizontal line direction in the SVE zigzag sensitivity patternillustrated in FIG. 1, there are two types of sensitivities in one line.Thus, because there are two types of exposure periods on one line in thehorizontal direction, at least two pixel transfer control signal linesTRG are necessary.

Here, a phenomenon that a CF sensitivity difference affects the qualityof an image has recently occurred while pixel size reduction hasprogressed. As a method of reducing the influence of the sensitivitydifference, a method of a color-specific shutter mechanism may be used.This color-specific shutter mechanism is a method of changing anexposure period for every filter color of each pixel and reducing theinfluence due to the sensitivity difference. When the exposure period ischanged for every filter color of each pixel, for example, the exposureperiod is lengthened for color pixels (for example, B and R pixels)having bad sensitivity and shortened for a color pixel (for example, a Gpixel) having good sensitivity. In addition, for a difference in theexposure period, processing is appropriately performed in a direction inwhich there is no difference in a calculation process.

In order to execute the color-specific shutter mechanism, a mechanismfor resetting a pixel at a different timing for every color isnecessary. Here, when the Bayer arrangement is considered, there are twotypes of color information on one line in the horizontal direction.Thus, at least two pixel transfer control signal lines connected forevery color pixel are necessary.

In addition, when a method of providing the color-specific shuttermechanism and implementing the SVE zigzag sensitivity patternillustrated in FIG. 1 is considered, the G pixels on one line in thehorizontal direction have the same sensitivity in the SVE zigzagsensitivity pattern. On the other hand, the R or B pixel has two typesof sensitivities of the long-time exposure and the short-time exposure.That is, for the pixel transfer control signal lines TRG connected tothe B and R pixels, it is necessary for the exposure period to be set astwo types of exposure periods. Thus, although at least one pixeltransfer control signal line TRG connected to the G pixel can beprovided, at least two pixel transfer control signal lines TRG connectedto the R or B pixel are necessary. Thus, at least three pixel transfercontrol signal lines TRG are necessary in one line in the horizontaldirection.

That is, the image sensor 100 has at least three pixel transfer controlsignal lines for controlling exposure start and end timings of eachpixel on a per line basis so that exposure timings of a plurality ofpixels constituting one line in a specific direction have at least threepatterns.

In addition, in one line, at least one pixel transfer control signalline is connected to a pixel of first spectral sensitivity constitutinga plurality of pixels, and at least two pixel transfer control signallines are connected to a pixel of second or third spectral sensitivityconstituting the plurality of pixels.

Here, a line on which the pixel of the first spectral sensitivity andthe pixel of the second spectral sensitivity constituting the pluralityof pixels in the specific direction (for example, the horizontaldirection) are alternately arranged is designated as a first line. Inaddition, a line on which the pixel of the first spectral sensitivityand the pixel of the third spectral sensitivity constituting theplurality of pixels in the specific direction are alternately arrangedis designated as a second line. In this case, in the image sensor 100,the first line and the second line are alternately arranged in anorthogonal direction (for example, the vertical direction).

[Timing Chart Example of Control Signals]

FIG. 4 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology. In FIG. 4, the timing chartcorresponding to pixels 201 to 206 among the pixels illustrated in FIG.3 is illustrated. In FIG. 1, the pixels 201 to 206 surrounded by a thickrectangular frame are illustrated. In addition, in FIG. 4, the timingchart for implementing the SVE zigzag sensitivity pattern isillustrated.

In addition, a horizontal axis illustrated in FIG. 4 is a time axis.Each waveform illustrated in FIG. 4 denoted by the same reference signas in a corresponding signal line illustrated in FIG. 3 will bedescribed. In addition, exposure periods E1 and E2 are periodscorresponding to long-time-exposure periods, and exposure periods E3 andE4 are periods corresponding to short-time-exposure periods. In FIG. 4,for ease of understanding, an example in which a color-specific exposureperiod by a color-specific shutter is not changed is illustrated.

As illustrated in FIG. 3, a pixel reset control signal line (RST) 171 ofthe pixels 201 to 203 (R19, G20, and R21) is common.

Here, a pixel electronic shutter means that an operation of turning onthe image reset control signal line RST (at a high (H) level because thereset transistor M2 is an N-channel MOSFET (NMOS)) and an operation ofactivating the pixel transfer control signal line TRG are simultaneouslyperformed. According to this pixel electronic shutter, chargesaccumulated in the PD (photodiode) serving as a target are reset. Thus,if the pixel transfer control signal line TRG is turned off even whenthe pixel reset control signal line RST is turned on, the target PD isnot reset.

For example, at time t1, because the pixel reset control signal line(RST) 171 and pixel transfer control signal lines (TRG) 172 and 173 areturned on, the pixel electronic shutters of the pixels 202 and 203 arereleased. Thus, during a period (the exposure period E1) from time t1 totime t5, the pixels 202 and 203 are exposed to light.

In addition, at time t3, because the pixel reset control signal line(RST) 171 and the pixel transfer control signal line (TRG) 173 areturned on, the pixel electronic shutter of the pixel 201 is released.Thus, during a period (the exposure period E1) from time t3 to time t5,the pixel 201 is exposed to light.

As described above, each pixel can be controlled so that a plurality ofpixels on one line in the horizontal direction are exposed to light indifferent exposure periods.

In addition, likewise, it is possible to perform control even for thenext line (pixels 204 to 206 (B26, G27, and B28)).

For example, at time t2, because a pixel reset control signal line (RST)176 and a pixel transfer control signal line (TRG) 179 are turned on,the pixel electronic shutter of the pixel 206 is released. Thus, duringa period (the exposure period E2) from time t2 to time t6, the pixel 206is exposed to light.

In addition, at time t4, because the pixel reset control signal line(RST) 176 and the pixel transfer control signal lines (TRG) 177 and 178are turned on, the pixel electronic shutters of the pixels 204 and 205are released. Thus, during a period (the exposure period E4) from timet4 to time t6, the pixels 204 and 205 are exposed to light. Here, it isestablished that Exposure Period E1=E2 and Exposure Period E3=E4.

As described above, at a pixel-reset timing, a desired sensitivitypattern can be generated by appropriately controlling ON/OFF of threepixel transfer control signal lines TRG in one line in the horizontaldirection.

In addition, for example, it is possible to switch arrangements of thelong-time-exposure pixels and the short-time-exposure pixels byswitching ON/OFF of the pixel transfer control signal lines TRG at timest1 to t6. Arrangement examples are illustrated in FIGS. 5 and 7, andexamples of timing charts corresponding thereto are illustrated in FIGS.6 and 8.

[Pixel Arrangement Example and Timing Chart Example]

Here, an example in which the arrangements of the long-time-exposurepixels and the short-time-exposure pixels are switched will bedescribed.

FIG. 5 is a diagram illustrating an example of the pixel arrangement ofCFs mounted on the light receiving section of the image sensor 100 inaccordance with the first embodiment of the present technology. FIG. 5is a modified example of FIG. 1, and is different from FIG. 1 in thatthe arrangements of the long-time-exposure pixels and theshort-time-exposure pixels are switched. However, except for the abovepoint, FIG. 5 is substantially the same as FIG. 1. Thus, parts common tothose of FIG. 1 are denoted by the same reference signs as in FIG. 1 anddetailed description thereof is omitted.

FIG. 6 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology. In FIG. 6, a timing chart forimplementing the arrangements of the long-time-exposure pixels and theshort-time-exposure pixels illustrated in FIG. 5 is illustrated.

FIG. 6 is a modified example of FIG. 4, and is different from FIG. 4 inthat ON/OFF of the pixel transfer control signal lines TRG at times t1to t6 is switched. However, except for the above point, FIG. 6 issubstantially the same as FIG. 4. Thus, parts common to those of FIG. 4are denoted by the same reference signs as in FIG. 4 and detaileddescription thereof is omitted.

As illustrated in FIGS. 5 and 6, it is possible to switch thearrangements of the long-time-exposure pixels and theshort-time-exposure pixels by switching ON/OFF of the pixel transfercontrol signal lines TRG at times t1 to t6.

[Pixel Arrangement Example and Timing Chart Example]

Here, an example in which a direction of the SVE zigzag sensitivitypattern is changed will be described.

FIG. 7 is a diagram illustrating an example of the pixel arrangement ofCFs mounted on the light receiving section of the image sensor 100 inaccordance with the first embodiment of the present technology. FIG. 7is a modified example of FIG. 1, and is different from FIG. 1 in thatthe direction of the SVE zigzag sensitivity pattern is switched.However, except for the above point, FIG. 7 is substantially the same asFIG. 1. Thus, parts common to those of FIG. 1 are denoted by the samereference signs as in FIG. 1 and detailed description thereof isomitted.

FIG. 8 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology. In FIG. 8, the timing chart forimplementing an arrangement in which the direction of the SVE zigzagsensitivity pattern illustrated in FIG. 7 has been changed isillustrated.

FIG. 8 is a modified example of FIG. 4, and is different from FIG. 4 inthat ON/OFF of the pixel transfer control signal lines TRG at times t1to t6 is switched. However, except for the above point, FIG. 8 issubstantially the same as FIG. 4. Thus, parts common to those of FIG. 4are denoted by the same reference signs as in FIG. 4 and detaileddescription thereof is omitted.

As illustrated in FIGS. 7 and 8, the direction of the SVE zigzagsensitivity pattern can be changed by switching ON/OFF of the pixeltransfer control signal lines TRG at times t1 to t6.

As described above, a desired SVE zigzag sensitivity pattern can begenerated by providing three pixel transfer control signal lines TRG inone line in the horizontal direction and switching pixel electronicshutter timings.

[Color-Specific Shutter Control Example]

Next, an example in which a color-specific shutter is controlled foreach pixel constituting the image sensor 100 will be described. First, acontrol timing example when the color-specific shutter is controlledaccording to a general single-exposure imaging method instead of the SVEzigzag sensitivity pattern will be described (FIG. 9). Next, a controltiming example for controlling the color-specific shutter andimplementing the SVE zigzag sensitivity pattern will be described (FIG.10).

[Timing Chart Example of Control Signals]

FIG. 9 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology. In FIG. 9, the timing chart forimplementing the color-specific shutter according to the generalsingle-exposure imaging method in the image sensor 100 illustrated inFIG. 3 is illustrated. Because FIG. 9 is a modified example of FIG. 4,signal lines common to those of FIG. 4 are denoted by the same referencesigns as in FIG. 4 and detailed description thereof is omitted.

As described above, sensitivity is different for every color of the CFsaccording to pixel size reduction and hence a sufficient signal amountis likely not to be obtained in a low-sensitivity pixel. Thus, it isimportant to reduce the adverse effect of such a sensitivity differenceon final signal processing. For example, because a G pixel generally hashigher sensitivity than R and B pixels, an exposure period for the Gpixel can be set to be shorter. As described above, there is consideredto be a difference in an exposure period for every type of pixel andhence a method (color-specific shutter) of offsetting a CF sensitivitydifference may be employed.

For example, at time t11, because the pixel reset control signal line(RST) 171 and the pixel transfer control signal lines (TRG) 172 and 174are turned on, the pixel electronic shutters of the pixels 201 and 203are released. In addition, at time t12, because the pixel reset controlsignal line (RST) 171 and the pixel transfer control signal line (TRG)173 are turned on, the pixel electronic shutter of the pixel 202 isreleased. That is, the pixel electronic shutter of the R pixel isreleased at the timing of time t11, and the pixel electronic shutter ofthe G pixel is released at the timing of time t12. At the timing of timet5, the pixels 201 to 203 connected to the pixel transfer control signallines (TRG) 172 to 174 are simultaneously read. That is, the pixels 201and 203 are exposed to light during a period (an exposure period E11 )from time t11 to time t15, and the pixel 202 is exposed to light duringa period (an exposure period E12) from time t12 to time t15.

As described above, it is possible to generate an exposure perioddifference between the exposure periods E11 and E12 and offset a CFsensitivity difference in the exposure period. That is, because twoexposure control operations are necessary in one line in the horizontaldirection when the color-specific shutter is operated, at least twopixel transfer control signal lines (TRG) are necessary.

Even for the pixels 204 to 206, it is possible to generate an exposureperiod difference between exposure periods E13 and E14 and offset a CFsensitivity difference in the exposure period.

[Timing Chart Example of Control Signals]

FIG. 10 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 100 in accordance with the firstembodiment of the present technology. In FIG. 10, the timing chart foroperating the color-specific shutter and implementing the SVE zigzagsensitivity pattern in the image sensor 100 illustrated in FIG. 3 isillustrated.

Because FIG. 10 is a modified example of FIG. 9, signal lines common tothose of FIG. 9 are denoted by the same reference signs as in FIG. 9 anddetailed description thereof is omitted. In addition, in FIG. 10, amongthe timings illustrated in FIG. 9, the timing of the pixel electronicshutter of the pixel transfer signal line (TRG) 174 is different.

That is, because the pixel transfer signal line (TRG) 174 is connectedto a pixel (R pixel) 201, and is provided to a short-time-exposurepixel, control is performed to set an exposure period SE1 shorter thanan exposure period LE1 of the long-time-exposure pixel.

For example, at time t21, because the pixel reset control signal line(RST) 171 and the pixel transfer control signal line (TRG) 172 areturned on, the pixel electronic shutter of the pixel (R pixel) 203 isreleased. In addition, at time t22, because the pixel reset controlsignal line (RST) 171 and the pixel transfer control signal line (TRG)173 are turned on, the pixel electronic shutter of the pixel (G pixel)202 is released.

In addition, at time t24, because the pixel reset control signal line(RST) 171 and the pixel transfer control signal line (TRG) 174 areturned on, the pixel electronic shutter of the pixel (R pixel) 201 isreleased. That is, the pixel electronic shutter of the R pixel isreleased at the timings of times t21 and t24, and the pixel electronicshutter of the G pixel is released at the timing of time t22.

At the timing of time t27, the pixels 201 to 203 connected to the pixeltransfer control signal lines (TRG) 172 to 174 are simultaneously read.That is, the pixel 203 is exposed to light during a period (the exposureperiod LE1 ) from time t21 to time t27, and the pixel 202 is exposed tolight during a period (an exposure period LE2) from time t22 to timet27. As described above, an exposure period difference between theexposure periods LE1 and LE2 is generated in the long-time-exposurepixels (R and G pixels). In addition, the pixel 201 is exposed to lightduring a period (the exposure period SE1) from time t24 to time t27.

As described above, it is possible to generate an exposure perioddifference between the exposure periods LE1 and LE2 of thelong-time-exposure pixels (R and G pixels) and offset a CF sensitivitydifference in the exposure period. That is, when the color-specificshutter is operated and the SVE zigzag sensitivity pattern isimplemented, it is necessary to control long-time exposure andshort-time exposure of the R and B pixels, and at least two pixeltransfer control signal lines TRG are necessary. In this case, for the Gpixel and the R or B pixel, it is necessary to divide the pixel transfercontrol signal lines TRG so as to operate the color-specific shutters.Thus, at least three pixel transfer control signal lines are necessaryin one line in the horizontal direction.

Even for the pixels 204 to 206, it is possible to generate an exposureperiod difference between exposure periods SE2 and SE3 of theshort-time-exposure pixels (B and G pixels) and offset a CF sensitivitydifference in the exposure period.

As described above, in the first embodiment of the present technology,using at least two pixel transfer control signal lines in a first line,some pixels constituting the first line are designated aslong-time-exposure pixels (first pixels) and the other pixelsconstituting the first line are designated as short-time-exposure pixels(second pixels). Likewise, using at least two pixel transfer controlsignal lines in a second line, some pixels constituting the second lineare designated as long-time-exposure pixels (first pixels) and the otherpixels constituting the second line are designated asshort-time-exposure pixels (second pixels).

In addition, in one line, using at least two pixel transfer controlsignal lines, the exposure period of the G pixel constituting thelong-time-exposure pixels (first pixels) is set to be shorter than thatof the R or B pixel constituting the first pixels.

In addition, in one line, using at least two pixel transfer controlsignal lines, the exposure period of the G pixel constituting theshort-time-exposure pixels (second pixels) is set to be shorter thanthat of the R or B pixel constituting the short-time-exposure pixels(second pixels).

In addition, the first embodiment of the present technology can berecognized as an imaging method of controlling exposure start and endtimings of each pixel so that exposure timings of a plurality of pixelsconstituting one line have at least three patterns using three pixeltransfer control signal lines.

As described above, in the first embodiment of the present technology,it is possible to implement the SVE zigzag sensitivity pattern in theCIS by providing three pixel transfer control signal lines TRG on oneline in the horizontal direction and controlling these pixel transfercontrol signal lines TRG. In addition, it is possible to implement theSVE zigzag sensitivity pattern even in the CIS that operates thecolor-specific shutter for ensuring a CF sensitivity difference. Inaddition, it is possible to implement the SVE zigzag sensitivity patterneven in a circuit configuration that performs time-division reading. Inaddition, although there is a certain extent of limitation, a desiredpixel sensitivity pattern can be generated by controlling the pixeltransfer control signal lines TRG. That is, it is possible to performappropriate imaging control in accordance with the first embodiment ofthe present technology.

<2. Second Embodiment>

In the first embodiment of the present technology, an example in whichthree pixel transfer control signal lines are provided on one line inthe horizontal direction to provide the color-specific shutter mechanismand to implement the SVE zigzag sensitivity pattern has been described.Here, an image sensor in which three pixel transfer control signal linesare necessary is also considered even when no color-specific shuttermechanism is provided. For example, the three pixel transfer controlsignal lines are necessary in the case of a circuit configuration inwhich one A/D converter is mounted for two pixels in the verticaldirection.

In the second embodiment of the present technology, another example ofthe image sensor in which the three pixel transfer control signal linesare necessary is shown.

[Configuration Example of Pixel Control Circuit and Pixel Wiring]

FIG. 11 is a diagram illustrating the configuration example of the pixelcontrol circuit and the pixel wiring of an image sensor 300 inaccordance with the second embodiment of the present technology. Becausethe image sensor 300 is a modified example of the image sensor 100illustrated in FIG. 3, part of description of sections common to theimage sensor 100 is omitted.

The image sensor 300 includes a vertical scanning control circuit 310, ahorizontal transfer circuit 320, column switches 331 to 334, A/Dconverters 335 to 338, memories 341 to 344, and a plurality of pixels(pixels R1to B48). The vertical scanning control circuit 310 correspondsto the vertical scanning control circuit 110 illustrated in FIG. 3, andthe horizontal transfer circuit 320 corresponds to the horizontaltransfer circuit 120 illustrated in FIG. 3. In addition, the pluralityof pixels (pixels R1 to B48) correspond to the plurality of pixels(pixels R1 to B48 ) illustrated in FIG. 3.

The column switches 331 to 334 select signals from two pixels based onsignals from a control section (not illustrated), and output theselected signals to the A/D converters 335 to 338.

The A/D converters 335 to 338 convert image data (analog values) fromthe column switches 331 to 334 into digital data (digital values).

The memories 341 to 344 sequentially store the digital data converted bythe A/D converters 335 to 338.

Here, although the A/D converter (A/D conversion circuit) is generallymounted according to a pixel pitch, the reduction of the A/D converterdoes not fit into the pixel pitch because of the design constraintaccording to an influence of pixel size reduction. Thus, as illustratedin FIG. 11, an image sensor in which one A/D converter is mounted in apitch of two pixels is proposed.

However, because one A/D converter reads from only one pixel once, it isnecessary to divide an operation of reading from two pixels into twooperations and perform the two operations when one A/D converter ismounted in the two pixels in one line in the horizontal direction.

For example, pixels 401 and 402 are located on the same line in thehorizontal direction, and connected to vertical signal lines (VSL) 353and 354, respectively. In addition, the vertical signal lines (VSL) 353and 354 are connected to the same A/D converter 336. Thus, it isdifficult to simultaneously read from the pixels 401 and 402. Forexample, it is necessary to shift a reading time of each pixel. Forexample, it is possible to adopt a method of performing the reading ofthe pixel 402 after the reading of the pixel 401 has ended. In thiscase, a time taken for A/D conversion in one line in the horizontaldirection is doubled.

Here, the timing of the pixel electronic shutter will be described.Here, for ease of description, reading in a single exposure periodinstead of SVE reading as the pixel electronic shutter will bedescribed.

In general, when time-division reading is not performed, it is necessaryfor the exposure period of a pixel of a row of a certain target to beread to be same as the exposure period of a pixel of another row to beread. Thus, the vertical scanning control circuit 310 controls eachsignal line so that time differences between the read timings of allrows and the timings of the pixel electronic shutters are the same.

In addition, likewise, even when the time-division reading is performed,it is necessary to release the pixel electronic shutter so that exposureperiods of the read timing of each pixel and the timing of the pixelelectronic shutter are the same. That is, pixels connected to the sameA/D converter on the same line in the horizontal direction are read atdifferent read timings. Thus, it is necessary to release the pixelelectronic shutter so that exposure periods of the read timing of eachpixel and the timing of the pixel electronic shutter are the same.

[Timing Chart Example of Control Signals]

FIG. 12 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 300 in accordance with the secondembodiment of the present technology. In FIG. 12, the timing chart forimplementing the SVE zigzag sensitivity pattern in the image sensor 300illustrated in FIG. 11 is illustrated. In addition, in FIG. 12, a timingchart corresponding to pixels 401 to 406 among pixels illustrated inFIG. 11 is illustrated.

For example, at time t31, because a pixel reset control signal line(RST) 371 and a pixel transfer control signal line (TRG) 372 are turnedon, the pixel electronic shutter of the pixel (R pixel) 403 is released.In addition, at time t32, because the pixel reset control signal line(RST) 371 and a pixel transfer control signal line (TRG) 373 are turnedon, the pixel electronic shutter of the pixel (G pixel) 402 is released.That is, because the read timings (times t37 and t38) of the pixels 403and 402 are shifted, the timings (times t31 and t32) of the pixelelectronic shutters of the pixels 403 and 402 are shifted by adifference between the read timings. In addition, the pixel 403 isexposed to light during a period (an exposure period E21) from time t31to time t37, and the pixel 402 is exposed to light during a period (anexposure period E22) from time t32 to time t38. It is established thatExposure Period E21=E22.

In addition, at time t34, because the pixel reset control signal line(RST) 371 and a pixel transfer control signal line (TRG) 374 are turnedon, the pixel electronic shutter of the pixel (R pixel) 401 is released.The pixel (R pixel) 401 is read at time t37. That is, the pixel 401 isexposed to light during a period (an exposure period E24) from time t34to time t37.

As described above, exposure is controlled at two sensitivities of thelong-time-exposure periods E21 and E22 and the short-time-exposureperiod E24 for implementing the state in which all the pixel electronicshutters of the pixels 401 to 403 on the same line in the horizontaldirection are released and the SVE zigzag sensitivity pattern. Thereby,a reading method and pixel electronic shutter control for time-divisionreading can be performed.

In addition, a pixel electronic shutter operation is performed at timet33, and the pixel 406 is exposed to light during a period (an exposureperiod E33) from time t33 to time t40. In addition, a pixel electronicshutter operation is performed at time t35, and the pixel 405 is exposedto light during a period (an exposure period E25) from time t35 to timet39. In addition, a pixel electronic shutter operation is performed attime t36, and the pixel 404 is exposed to light during a period (anexposure period E26) from time t36 to time t40. Here, it is establishedthat Exposure Period E21=E22=E23 and Exposure Period E24=E25=E26.

As described above, in the second embodiment of the present technology,at least three pixel transfer control signal lines are provided in oneline in the horizontal direction in a circuit configuration in which oneA/D converter is mounted in a pitch of two pixels. That is, at least twopixel transfer gate signal lines are necessary for two pixels of oneline in the horizontal direction in which reading is performed in oneA/D converter because it is necessary to shift the timing at which agate is turned on during reading. In addition, when the SVE zigzagsensitivity pattern is implemented, it is necessary to divide the pixeltransfer control signal lines because it is necessary to vary theexposure period for the adjacent R or B pixels between which the G pixelis interposed on one line in the horizontal direction. As describedabove, it is possible to implement the SVE zigzag sensitivity pattern ina circuit configuration in which one A/D converter is mounted in a pitchof two pixels by providing at least three pixel transfer control signallines on one line in the horizontal direction. That is, it is possibleto perform appropriate imaging control in accordance with the secondembodiment of the present technology.

<3. Third Embodiment>

In the first and second embodiments of the present technology, anexample in which a signal read from each pixel is used without beingadded has been described. Here, there is also an image sensor that addsand uses a signal read from each pixel.

In the third embodiment of the present technology, an example of animage sensor that adds and uses a signal read from each pixel is shown.

[Arrangement Example of Pixels]

FIG. 13 is a diagram illustrating an example of a pixel arrangement ofCFs mounted on a light receiving section of an image sensor 500 inaccordance with the third embodiment of the present technology. FIG. 13is a modified example of FIG. 1, and is different from FIG. 1 in thatarrangements of the long-time-exposure pixels and theshort-time-exposure pixels are switched. However, except for the abovepoint, FIG. 13 is substantially the same as FIG. 1. Thus, parts commonto those of FIG. 1 are denoted by the same reference signs as in FIG. 1and detailed description thereof is omitted.

In addition, in FIG. 13, an example of a pixel arrangement serving asthe SVE zigzag sensitivity pattern illustrated in FIG. 14 aftertwo-pixel addition has been performed is illustrated.

Here, an addition method of obtaining an output added (added andaveraged) in the longitudinal direction according to pixel driving andperforming addition in a logical calculation in the lateral direction soas to match an aspect ratio of an angle of view after passing throughthe horizontal transfer circuit is usually used as pixel addition.

In FIG. 13, an example in which a pixel on one line in the horizontaldirection and a pixel having the same color as the pixel and separatedby two pixels in a downward direction (or two pixels in an upwarddirection) from the pixel are simultaneously read and reading resultsare added is illustrated. For example, for pixels (pixels within adotted rectangular frame) constituting an R/G pixel addition line 451and pixels (pixels within a dotted rectangular frame) constituting anR/G pixel addition line 453, addition is performed between pixels in thevertical direction (longitudinal direction). Likewise, addition isperformed between pixels in the vertical direction for pixelsconstituting a B/G pixel addition line 452 and pixels constituting a B/Gpixel addition line 454. In addition, likewise, addition is performedbetween pixels in the vertical direction even for R/G pixel additionlines 455 and 457 and B/G pixel addition lines 456 and 458. Two pixelsserving as addition targets have the same color and it is necessary tomatch the exposure periods of the two pixels.

As described above, pixel addition is performed and hence the number ofpixels in the longitudinal direction is halved for an output to thehorizontal transfer circuit. An arrangement example after the pixeladdition is illustrated in FIG. 14.

[Output Example after Pixel Addition]

FIG. 14 is a diagram illustrating an output example after pixel additionperformed on pixels constituting the image sensor 500 in accordance withthe third embodiment of the present technology. That is, in FIG. 14, anoutput example after pixels have been added and read for anexposure-controlled sensitivity pattern illustrated in FIG. 13 isillustrated.

Pixels within a thick rectangular frame 471 illustrated in FIG. 14correspond to outputs of pixel addition performed on pixels within athick rectangular frame 461 illustrated in FIG. 13. In addition, pixelswithin a dotted rectangular frame 472 illustrated in FIG. 14 correspondto outputs of pixel addition performed on pixels within a dottedrectangular frame 462 illustrated in FIG. 13.

For example, pixels of an upper-side line within the thick rectangularframe 471 correspond to outputs of pixel addition performed on thepixels constituting the R/G pixel addition line 451 and the pixelsconstituting the R/G pixel addition line 453 illustrated in FIG. 13. Inaddition, pixels of a lower-side line within the thick rectangular frame471 correspond to outputs of pixel addition performed on the pixelsconstituting the B/G pixel addition line 452 and the pixels constitutingthe B/G pixel addition line 454 illustrated in FIG. 13.

As illustrated in FIG. 14, a pattern of pixel data after pixel additionhas been performed in the arrangement illustrated in FIG. 13 has thesame arrangement as the SVE zigzag sensitivity pattern. Thus, because itis possible to use the same signal processing as in the SVE zigzagsensitivity pattern even for a pixel addition operation, it is possibleto suppress an increase in a circuit scale.

[Configuration Example of Pixel Circuit Shared by Four Pixels inLongitudinal Direction]

FIG. 15 is a diagram illustrating a configuration example of a basiccircuit of a pixel provided in the image sensor 500 in accordance withthe third embodiment of the present technology. In FIG. 15, aconfiguration example of a pixel circuit of a CIS shared by four pixelsin the longitudinal direction is illustrated.

In FIG. 15, the pixel circuit shared by the four pixels in thelongitudinal direction in which pixels pd0 to pd3 continuously arrangedin the longitudinal direction are connected to one FD fd via pixeltransfer transistors trs0 to trs3 is illustrated. In addition, thesepixels are connected to pixel transfer control signal lines trg0 totrg3, a pixel read selection control signal line sel, a vertical signalline (read line) vsl, and a pixel reset control signal line rst.

Because a configuration and operation are substantially the same asthose of the pixel circuit illustrated in FIG. 2, except that the pixelcircuit is shared by the four pixels in the longitudinal direction,detailed description is omitted here.

[Configuration Example of Pixel Control Circuit and Pixel Wiring]

FIG. 16 is a diagram illustrating the configuration example of the pixelcontrol circuit and the pixel wiring of the image sensor 500 inaccordance with the third embodiment of the present technology. That is,in FIG. 16, an example of an SVE control circuit when a pixel circuitshared by four pixels in the longitudinal direction has been used isillustrated. Because the image sensor 500 is a modified example of theimage sensor 100 illustrated in FIG. 3, part of description of sectionscommon to the image sensor 100 is omitted.

Here, although the pixel reset control signal line RST and the pixelread selection control signal line SEL are conveniently connected toeach pixel in FIG. 16, a reset operation is performed only when a resetactivation signal has been input to a pixel of which the pixel transfercontrol signal line TRG is activated. In addition, a read operation isperformed only on a pixel of which the pixel read selection controlsignal line SEL and the pixel transfer control signal line TRG have beensimultaneously activated.

In addition, the pixel read selection control signal line SEL isconnected to the pixel read selection control signal line selillustrated in FIG. 15, and the pixel reset control signal line RST isconnected to the pixel reset control signal line rst.

[Timing Chart Example of Control Signals (Digital Addition)]

FIG. 17 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 500 in accordance with the thirdembodiment of the present technology. In FIG. 17, the timing chart forimplementing the SVE zigzag sensitivity pattern illustrated in FIG. 14in the image sensor 500 illustrated in FIG. 16 is illustrated. Inaddition, in FIG. 17, the timing chart when digital addition is used isillustrated. For ease of description, an example in which acolor-specific shutter mechanism is not used is illustrated in FIG. 17.

Here, digital addition is a method of performing an addition operationcorresponding to two pixels by obtaining an A/D conversion valueaccording to A/D conversion of one pixel of the two pixels that areaddition targets and then reading another pixel in addition to the A/Dconversion value.

For example, pixels of one line in the horizontal direction connected topixel transfer control signal lines (TRG) 562 to 564 illustrated in FIG.16 are simultaneously read at the timing of time t49. After A/Dconversion by the A/D converters 531 to 536 has ended for data read asdescribed above, each pixel of one line in the horizontal directionconnected to pixel transfer control signal lines (TRG) 568 to 570, whichare addition targets, is read at the timing of time t50. At this time,A/D conversion data read at the timing of time t50 is added to A/Dconversion data read at the timing of time t49.

Thereafter, the added data is stored in the memories 541 to 546 arrangedin columns, and the horizontal transfer circuit 520 transmits the addeddata to a subsequent-stage calculation circuit (not illustrated).

Here, when the SVE zigzag sensitivity pattern is implemented, it isnecessary to control exposure in an exposure period so that anarrangement is provided as illustrated in FIG. 13. Hereinafter, anexposure control example will be described.

In FIG. 17, pixels on which long-time exposure is performed areconnected to pixel transfer control signal lines (TRG) 562, 563, 567,569, 570, and 571. Among these, the pixel transfer control signal lines(TRG) 562 and 563 through which reading is performed at the timing oftime t49 are provided, and the exposure period is an exposure periodE31.

In addition, it is necessary for the exposure period E32 of pixels(pixels (pixels read at time t50) connected to the pixel transfercontrol signal lines (TRG) 567 and 570) serving as addition targets tobe set to be the same as the exposure period E31. Thus, the pixelelectronic shutter is released at the timing of time t42 correspondingto a difference between time t49 and time t50. That is, it isestablished that Exposure Period E32=E31.

In addition, the pixel electronic shutter is released at the timing oftime t45 so that a pixel connected to the pixel transfer control signalline (TRG) 564 arranged on the same line in the horizontal direction asthe pixel transfer control signal lines (TRG) 562 and 563 has ashort-time-exposure period E33.

In addition, as in control of the long-time exposure, it is necessaryfor an exposure period E34of the pixel of the addition target (a pixelconnected to the pixel transfer control signal line (TRG) 568 (a pixelread at time t50)) to be set to be the same as the exposure period E33.Thus, the pixel electronic shutter is released at the timing of time t46corresponding to the difference between time t49 and time t50. That is,it is established that Exposure Period E33=E34.

Likewise, even for B and G pixels connected to pixel transfer controlsignal lines (TRG) 565 to 567 and pixel transfer control signal lines(TRG) 571 to 573, control is performed so that the relations ofLong-Time-Exposure Period E35=E36 and Short-Time-Exposure Period E37=E38are established. That is, control is performed so that the sensitivitypattern illustrated in FIG. 13 is provided.

[Timing Chart Example (Analog Addition) of Control Signals]

FIG. 18 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 500 in accordance with the thirdembodiment of the present technology. In FIG. 18, the timing chart forimplementing the SVE zigzag sensitivity pattern illustrated in FIG. 14in the image sensor 500 illustrated in FIG. 16 is illustrated. Inaddition, in FIG. 18, the timing chart when the analog addition is usedis illustrated. For ease of description, in FIG. 18, an example in whichno color-specific shutter mechanism is used is illustrated.

Here, the analog addition is an addition method that is performed bysimultaneously completely transferring charges corresponding to two ormore pixels in an operation of transferring charges from a PD to an FDduring the read operation. For example, the transfer operations aresimultaneously performed on two pixels of the same color in the pixelcircuit shared by the four pixels in the longitudinal directionillustrated in FIG. 15 during the read operation.

For example, a pixel R15 to be read simultaneously when analog additionis performed on a pixel R3 connected to the pixel transfer controlsignal line (TRG) 562 illustrated in FIG. 16 is connected to the pixeltransfer control signal line (TRG) 570. Thus, the pixel electronicshutters are simultaneously released at the timing of time t61, and theread operations are simultaneously performed at the timing of time t65.

Likewise, even for the pixel transfer control signal lines (TRG) 563 and569 connected to pixels G2 and G14 illustrated in FIG. 16, the samecontrol is performed.

In addition, even for the pixel transfer control signal lines (TRG) 564and 568 connected to pixels R1 and R13 illustrated in FIG. 16, theaddition read operations are simultaneously performed at time t65.However, in this case, the pixel electronic shutters are simultaneouslyreleased at time t63 at which the exposure period has been shortened toperform SVE control.

In addition, for pixels separated by one pixel in the downward directionfrom the horizontal line to be read at time t66, at the timing of timet62, the pixel electronic shutters for pixels connected to the pixeltransfer control signal lines (TRG) 567 and 571 are released. In thiscase, the long-time-exposure control in SVE is performed, and the pixelelectronic shutters for the other pixels of one line in the horizontaldirection are released at the timing of time t64, and theshort-time-exposure control in SVE is performed. According to thiscontrol, the sensitivity pattern illustrated in FIG. 13 is implemented,and an output of an SVE zigzag sensitivity pixel arrangement asillustrated in FIG. 14 can be obtained for data after addition. Thereby,because the same signal processing as in the SVE zigzag sensitivitypattern can be used, it is possible to suppress an increase in a circuitscale. As described above, it is possible to perform appropriate imagingcontrol according to the third embodiment of the present technology.

As described above, in the third embodiment of the present technology,addition is performed on the same type of pixels in units of lines inthe vertical direction for pixels constituting two adjacent first linesin the vertical direction. Addition is performed on the same type ofpixels in units of lines in the vertical direction for pixelsconstituting two adjacent second lines in the vertical direction.Thereby, an arrangement of pixel signals after the addition can have aBayer arrangement (the SVE zigzag sensitivity pixel arrangementillustrated in FIG. 14).

<4. Fourth Embodiment>

In the third embodiment of the present technology, an example in whichthe pixel circuit shared by the four pixels in the longitudinaldirection is used has been described. Here, there is also an imagesensor that shares four or more pixels.

In the fourth embodiment of the present technology, an example of animage sensor using a pixel circuit shared by eight pixels will bedescribed.

[Configuration Example of Pixel Circuit Shared by Eight Pixels]

FIG. 19 is a diagram illustrating a configuration example of a basiccircuit of a pixel provided in an image sensor 700 in accordance withthe fourth embodiment of the present technology. In FIG. 19, aconfiguration example of a pixel circuit shared by eight pixels when oneFD is shared by four longitudinal pixels and two lateral pixels isillustrated.

As illustrated in FIG. 19, because another column pixel is added to thepixel circuit shared by the four pixels illustrated in FIG. 15, it isnecessary to separately provide pixel transfer control signal lines trg4to trg7 of one line in the horizontal direction. Because a configurationand operation are substantially the same as those of the pixel circuitillustrated in FIG. 15, except that the pixel transfer control signallines trg4 to trg7 are provided and the pixel circuit is shared by theeight pixels, detailed description is omitted here.

[Configuration Example of Pixel Control Circuit and Pixel Wiring]

FIG. 20 is a diagram illustrating the configuration example of the pixelcontrol circuit and the pixel wiring of the image sensor 700 inaccordance with the fourth embodiment of the present technology. Thatis, in FIG. 20, an example of an SVE control circuit when the pixelcircuit shared by eight pixels has been used is illustrated. Because theimage sensor 700 is a modified example of the image sensor 500illustrated in FIG. 16, description of sections common to the imagesensor 500 is partially omitted.

Here, in the image sensor 700, the number of vertical signal lines VSLis half the number of pixels in the horizontal direction because a pixelcircuit is shared by the two pixels in the lateral direction. Inaddition, because A/D converters 731 to 733 and the memories 741 to 743are connected one by one for one vertical signal line VSL, time-divisionreading in which A/D conversion is performed by dividing into odd andeven columns in one line in the horizontal direction is performed.

[Timing Chart Example (Analog Addition) of Control Signals]

FIG. 21 is a timing chart schematically illustrating control signals forpixels constituting the image sensor 700 in accordance with the fourthembodiment of the present technology. In FIG. 21, the timing chart forimplementing the SVE zigzag sensitivity pattern according to analogaddition reading in the image sensor 700 illustrated in FIG. 20 isillustrated. For ease of description, in FIG. 21, an example in which nocolor-specific shutter mechanism is used is illustrated.

In terms of pixels connected to pixel transfer control signal lines(TRG) 762 to 764, pixels serving as analog addition targets areconnected to pixel transfer control signal lines (TRG) 768 to 770.

Here, when analog addition is performed, it is necessary tosimultaneously set pixel electronic shutters and read timings of twopixels of the same color within a pixel shared circuit. For example, interms of an R pixel connected to the pixel transfer control signal line(TRG) 762, a pixel serving as an analog addition target is connected tothe pixel transfer control signal line (TRG) 770. Thus, pixel electronicshutters are simultaneously released at the timing of time t71, and readoperations are simultaneously performed at the timing of time t77. Inthis case, long-time exposure is performed as SVE exposure control andan exposure period E51 is provided.

In addition, in terms of a G pixel connected to the pixel transfercontrol signal line (TRG) 763, a pixel serving as an analog additiontarget is connected to the pixel transfer control signal line (TRG) 769.

Here, although the same long-time-exposure control as in the R pixelconnected to the pixel transfer control signal line (TRG) 762 isperformed as the SVE exposure control, it is necessary to performtime-division reading because pixels are adjacent on one line in thehorizontal direction. Thus, reading is performed at the timing of timet78.

For example, although pixel electronic shutters of pixels connected tothe pixel transfer control signal lines (TRG) 763 and 769 aresimultaneously released at the timing of time t72, time t72 isdetermined so that Exposure Period E5 =E51 is established.

In addition, the remaining pixels on the same line in the horizontaldirection (a pixel connected to the pixel transfer control signal line(TRG) 764) are controlled in short-time exposure. A pixel serving as ananalog addition target is connected to the pixel transfer control signalline (TRG) 768. In addition, because the pixel is the R pixel, readingis performed at the timing of time t77. In addition, for short-timeexposure, exposure control of an exposure period E54 shorter than theexposure periods E51 and E52 is performed. Thus, the pixel electronicshutter is released at the timing of time t74.

Next, a pixel row below one pixel will be described. For example, a Gpixel connected to the pixel transfer control signal line (TRG) 766 ofthe pixel transfer control signal lines (TRG) 765 to 767 is read at thetiming of time t79. A pixel serving as the analog addition target (apixel connected to the pixel transfer control signal line (TRG) 772) isalso simultaneously read at the timing of time t79. Because these pixelsare controlled in short-time exposure in SVE control, the pixelelectronic shutters are released at the timing of time t75 so that thesame exposure period as the exposure period E54 is provided

In addition, it is necessary to perform time-division reading on a pixelwhich is located in the same line in the horizontal line and issubjected to short-time exposure (a B pixel connected to the pixeltransfer control signal line (TRG) 765) and a B pixel connected to apixel transfer control signal line (TRG) 773 serving as the analogaddition target. That is, it is necessary to perform time-divisionreading by shifting the read timing of the B pixel with respect to a Gpixel, and reading is performed at the timing of time t80. In this case,because Exposure Period E56=E55 is established, the pixel electronicshutter is released at the timing of time t76.

In addition, the remaining pixels of the same line in the horizontaldirection (a pixel connected to the pixel transfer control signal line(TRG) 767) and a pixel serving as the analog addition target (a pixelconnected to a pixel transfer control signal line (TRG) 771) are read atthe timing of time t80. In this case, because it is necessary to performlong-time exposure according to SVE control for these pixels, the pixelelectronic shutters are released at the timing of time t73 so thatExposure Period E51=E53 is established.

According to the above operation, it is possible to generate an SVEexposure pattern before addition as illustrated in FIG. 13 even in thepixel circuit shared by the eight pixels. That is, it is possible toperform appropriate imaging control according to the fourth embodimentof the present technology.

<5. Fifth Embodiment>

In the first to fourth embodiments of the present technology, an examplein which three pixel transfer control signal lines of each pixelconstituting one line in the horizontal direction are provided has beendescribed. As described above, when the three pixel transfer controlsignal lines are provided, it is important to devise the layout so as toreduce the adverse effect of a load capacity of the pixel transfercontrol signal line.

In the fifth embodiment of the present technology, an example of thelayout for reducing the adverse effect of the load capacity of the pixeltransfer control signal line will be described.

[Layout Example of Pixel Transfer Control Signal Line]

FIG. 22 is a diagram schematically illustrating a layout example ofpixels and pixel transfer control signal lines constituting an imagesensor in accordance with the fifth embodiment of the presenttechnology.

In FIG. 22, each pixel is indicated by a rectangle, and a type of eachpixel is assigned within the rectangle. In addition, the pixel transfercontrol signal line TRG is indicated by a long rectangle in thehorizontal direction, and a rectangle marked by x in the inside isarranged and shown in a position of a pixel connected thereto.

As illustrated in FIG. 22, in the fifth embodiment of the presenttechnology, the pixel transfer control signal line TRG connected to theG pixel is arranged to be interposed between two pixel transfer controlsignal lines TRG of the R or B pixel.

For example, the number of pixels connected to each pixel transfercontrol signal line TRG in the case of the G pixels is twice that in thecase of the R or B pixels. Here, if the number of pixels connected tothe pixel transfer control signal line TRG is different, a load of itswiring is different and hence its difference is likely to be shown in animage when the image has been developed.

For example, when imaging has been performed in single exposure insteadof SVE, control is performed so that two image transfer control signallines TRG connected to the R pixel are simultaneously turned ON/OFF atthe pixel electronic shutter timing and the read timing.

It is possible to make a load such as a line capacity identical to thatof the G pixel by arranging one pixel transfer control signal line TRGconnected to the G pixel between the two pixel transfer control signallines TRG connected to the R or B pixel. Thus, it is possible to form astructure in which it is difficult for timing deviation to be caused bya load capacity between identical colors. In addition, appropriatecorrespondence to control signal lines of the R and B pixels isnecessary so that a control signal line and a power ground line areadditionally located within the pixel.

For example, it is possible to apply an image sensor (for example, seeJapanese Unexamined Patent Application Publication No. 2003-31785) inwhich a wiring layer forming wirings such as pixel transfer controlsignal lines is formed on a surface opposite a surface on which pixelsare formed. That is, it is possible to provide an image sensor in whicha wiring layer forming wirings such as three pixel transfer controlsignal lines is formed on the surface opposite the surface on which thepixels are formed. In this case, the three pixel transfer control signallines can be arranged to have the same height as the wiring layer.Thereby, it is possible to provide an image sensor corresponding topixel size reduction.

As described above, it is possible to reduce shading or the like orreduce an adverse effect of a load capacity of a control signal line bydevising the wiring arrangement or the order of physical position. Thatis, it is possible to perform appropriate imaging control according tothe fifth embodiment of the present technology.

<6. Application Example>

In the first to fifth embodiments of the present technology, examples ofimage sensors each having at least three pixel transfer control signallines connected to a plurality of pixels with different exposure timingsamong a plurality of pixels constituting one line has been described.Hereinafter, an example of an imaging apparatus having each of theseimage sensors will be described.

[Functional Configuration Example of Imaging Apparatus]

FIG. 23 is a block diagram illustrating a functional configurationexample of an imaging apparatus 800 in accordance with an embodiment ofthe present technology.

The imaging apparatus 800 includes an image sensor 810, an imageprocessing section 820, a recording control section 830, a contentstorage section 840, a display control section 850, a display section860, a control section 870, and an operation reception section 880.

The image sensor 810 generates an image signal based on an instructionof the control section 870, and outputs the generated image signal tothe image processing section 820. Specifically, the image sensor 810converts light of an object incident via an optical system (notillustrated) into an electrical signal. The image sensor 810 correspondsto an image sensor shown in each of the first to fifth embodiments ofthe present technology. In addition, the optical system includes a lensgroup and a diaphragm, which focuses incident light from the object, andthe light focused by the lens group is incident on the image sensor 810via the diaphragm.

The image processing section 820 performs various image processing on animage signal (digital signal) output from the image sensor 810 based onan instruction of the control section 870. The image processing section820 outputs the image signal (image data) subjected to various imageprocessing to the recording control section 830 and the display controlsection 850.

The recording control section 830 performs recording control on thecontent storage section 840 based on an instruction of the controlsection 870. For example, the recording control section 830 causes thecontent storage section 840 to record an image (image data) output fromthe image processing section 820 as image content (a still-image file ora moving-image file).

The content storage section 840 is a recording medium that storesvarious information (image content and the like) based on control of therecording control section 830. The content storage section 840 may beembedded in the imaging apparatus 800, and may be attachable to ordetachable from the imaging apparatus 800.

The display control section 850 causes the display section 860 todisplay an image output from the image processing section 820 based onan instruction of the control section 870. For example, the displaycontrol section 850 causes the display section 860 to display a displayscreen for performing various operations related to an imaging operationor an image (so-called through image) generated by the image sensor 810.

The display section 860 is a display panel that displays each imagebased on control of the display control section 850.

The control section 870 controls each section in the imaging apparatus800 based on a control program stored in a memory (not illustrated). Forexample, the control section 870 performs output control (displaycontrol) or recording control of an image signal (image data) subjectedto image processing by the image processing section 820.

The operation reception section 880 receives an operation performed by auser, and outputs a control signal (operation signal) corresponding toreceived operation content to the control section 870.

Although an example of the imaging apparatus 800 has been described inthis example, it is possible to apply the embodiment of the presenttechnology to electronic device (for example, a portable telephoneapparatus in which an imaging section is embedded) having an imagingsection with an image sensor.

In addition, an example in which three pixel transfer control signallines are provided on a per line basis has been described in theembodiment of the present technology. However, four or more pixeltransfer control signal lines may be provided on a per line basis andexposure start and end timings of each pixel may be controlled so thatthe exposure timings have four or more exposure timing patterns.

In addition, although an example in which spectral sensitivities ofpixels of the image sensor are three primary colors of RGB has beendescribed in the embodiment of the present technology, a pixel havingspectral sensitivity other than the three primary colors of RGB may beused. For example, it is possible to use a pixel having spectralsensitivity of a complementary color system such as yellow (Y), cyan(C), and magenta (M).

Because the above-described embodiment illustrates an example forimplementing the present technology, each item described in theembodiment and an item specifying the present technology in the claimshave a correspondence relationship. Likewise, the item specifying thepresent technology in the claims and an item to which the same name isassigned in the embodiment of the present technology have acorrespondence relationship. However, the present technology is notlimited to the embodiments and may be implemented by applying variousmodifications to the embodiments in the scope without departing from thesubject matter.

Additionally, the present technology may also be configured as below.

(1) An image sensor including:

at least three pixel transfer control signal lines, on a per line basis,configured to control exposure start and end timings of a pixel in orderfor exposure timings of a plurality of the pixels constituting one linein a specific direction to have at least three patterns.

(2) The image sensor according to (1), wherein a first line on which apixel of first spectral sensitivity and a pixel of second spectralsensitivity constituting the plurality of pixels are alternatelyarranged in the specific direction, and a second line on which a pixelof the first spectral sensitivity and a pixel of third spectralsensitivity constituting the plurality of pixels are alternatelyarranged in the specific direction are alternately arranged in anorthogonal direction orthogonal to the specific direction.(3) The image sensor according to (2),

wherein, using at least two pixel transfer control signal lines of thepixel transfer control signal lines in the first line, some pixelsconstituting the first line are designated as first pixels forgenerating a long-time-exposure image with continuous exposure within apredetermined period, and pixels constituting the first line, which areother than the some pixels, are designated as second pixels forgenerating a plurality of short-time-exposure images with intermittentexposure within the predetermined period, and

wherein, using at least two pixel transfer control signal lines of thepixel transfer control signal lines in the second line, some pixelsconstituting the second line are designated as the first pixels andpixels constituting the second line, which are other than the somepixels, are designated as the second pixels.

(4) The image sensor according to (3), wherein, using the pixel transfercontrol signal lines, a first pixel group in which a predeterminednumber of pixels in the specific direction and the predetermined numberof pixels in the orthogonal direction are connected stepwise isdesignated as the first pixels, a second pixel group in which thepredetermined number of pixels in the specific direction and thepredetermined number of pixels in the orthogonal direction are connectedstepwise is designated as the second pixels, and the first pixel groupand the second pixel group are alternately arranged in the specificdirection.(5) The image sensor according to (3) or (4), wherein, in the one line,using at least two pixel transfer control signal lines of the pixeltransfer control signal lines, an exposure period of the pixel of thefirst spectral sensitivity constituting the first pixels is set to beshorter than an exposure period of the pixel of the second or thirdspectral sensitivity constituting the first pixels.(6) The image sensor according to any one of (3) to (5), wherein, in theone line, using at least two pixel transfer control signal lines of thepixel transfer control signal lines, an exposure period of the pixel ofthe first spectral sensitivity constituting the second pixels is set tobe shorter than an exposure period of the pixel of the second or thirdspectral sensitivity constituting the second pixels.(7) The image sensor according to any one of (2) to (6), wherein anarrangement of the pixel of the first spectral sensitivity, the pixel ofthe second spectral sensitivity, and the pixel of the third spectralsensitivity is a Bayer arrangement.(8) The image sensor according to (2), wherein, by performing additionon a single type of pixels in units of lines in the orthogonal directionon pixels constituting two first lines adjacent in the orthogonaldirection and performing addition on a single type of pixels in units oflines of the orthogonal direction on pixels constituting two secondlines adjacent in the orthogonal direction, an arrangement of pixelsignals after the addition is a Bayer arrangement.(9) The image sensor according to any one of (2) to (8), wherein, in theone line, at least one pixel transfer control signal line is connectedto the pixel of the first spectral sensitivity constituting theplurality of pixels and at least two pixel transfer control signal linesare connected to the pixel of the second or third spectral sensitivityconstituting the plurality of pixels.(10) The image sensor according to (9), wherein the at least one pixeltransfer control signal line connected to the pixel of the firstspectral sensitivity is arranged between the at least two pixel transfercontrol signal lines connected to the pixel of the second or thirdspectral sensitivity.(11) The image sensor according to any one of (1) to (10), wherein thepixel of the first spectral sensitivity is a green (G) pixel, the pixelof the second spectral sensitivity is a red (R) pixel, and the pixel ofthe third spectral sensitivity is a blue (B) pixel.(12) The image sensor according to (1),

wherein the plurality of pixels share one analog/digital (A/D) converterbetween two adjacent pixels in the specific direction, and

wherein exposure timings of the two adjacent pixels are shifted using atleast two pixel transfer control signal lines among the pixel transfercontrol signal lines.

(13) The image sensor according to (1), wherein a pixel group formed bya plurality of pixels in the specific direction and a plurality ofpixels in an orthogonal direction shares one floating diffusion.

(14) An imaging apparatus including:

an image sensor configured to have at least three pixel transfer controlsignal lines on a per line basis for controlling exposure start and endtimings of a pixel in order for exposure timings of a plurality of thepixels constituting one line in a specific direction to have at leastthree patterns; and

an image processing section configured to perform image processing on animage signal output from the image sensor.

(15) An electronic device including:

an image sensor configured to have at least three pixel transfer controlsignal lines on a per line basis for controlling exposure start and endtimings of a pixel in order for exposure timings of a plurality of thepixels constituting one line in a specific direction to have at leastthree patterns;

an image processing section configured to perform image processing on animage signal output from the image sensor; and

a control section configured to control the image signal subjected tothe image processing to be output or recorded.

(16) An imaging method including:

controlling exposure start and end timings of a pixel using at leastthree pixel transfer control signal lines provided on a per line basisin a specific direction in order for exposure timings of a plurality ofpixels constituting one line to have at least three patterns.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2012-003997 filed in theJapan Patent Office on Jan. 12, 2012, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. An image sensor comprising: a pixel unit that hasa plurality of pixel groups, each of the plurality of pixel groupsincluding at least two photoelectric conversion elements that arearranged in a column direction and share a floating diffusion element;and wherein a first photoelectric conversion element has a firstexposure time and a second photoelectric conversion element that is in asame row as the first photoelectric conversion element and that is in adifferent pixel group than the first photoelectric conversion elementhas a second exposure time which is different from the first exposuretime, and wherein each of the plurality of pixel groups includes atleast four photoelectric conversion elements that are arranged in acolumn, at least two of which are of a same spectral sensitivity as oneanother.
 2. The image sensor of claim 1, wherein the first and secondphotoelectric conversion elements are of a same spectral sensitivity asone another.
 3. The image sensor of claim 1, wherein pixel signals areread out from the plurality of pixel groups such that, for a given pixelgroup, pixel signals from two photoelectric conversion elements that areof a same spectral sensitivity as one another are summed by digitaladdition.
 4. The image sensor of claim 3, wherein, for the given pixelgroup, those photoelectric conversion elements whose pixel signals aresummed have a same exposure time as one another.
 5. The image sensor ofclaim 1, wherein pixel signals are read out from the plurality of pixelgroups such that, for a given pixel group, pixel signals from twophotoelectric conversion elements that are of a same spectralsensitivity as one anther are summed by analog addition.
 6. The imagesensor of claim 5, wherein, for the given pixel group, thosephotoelectric conversion elements whose pixel signals are summed have asame exposure time as one another.
 7. The image sensor of claim 1,wherein the plurality of pixel groups includes a first type of pixelgroup and a second type of pixel group, the first type of pixel groupincludes two photoelectric conversion elements of a first spectralsensitivity and two photoelectric conversion elements of a secondspectral sensitivity, and the second type of pixel group includes twophotoelectric conversion elements of the first spectral sensitivity andtwo photoelectric conversion elements of a third spectral sensitivity.8. The image sensor of claim 7, wherein the plurality of pixel groupsare arranged so as to alternate between the first type of pixel groupand the second type of pixel group in a row direction.
 9. An imagingapparatus, comprising: the image sensor of claim 1, and a lens unit thatfocuses incident light on the pixel unit.
 10. An image sensorcomprising: a pixel unit that has a plurality of pixel groups, each ofthe plurality of pixel groups including at least two photoelectricconversion elements that are arranged in a column direction and share afloating diffusion element; and wherein a first photoelectric conversionelement has a first exposure time and a second photoelectric conversionelement that is in a same row as the first photoelectric conversionelement and that is in a different pixel group than the firstphotoelectric conversion element has a second exposure time which isdifferent from the first exposure time, and wherein each of theplurality of pixel groups includes at least eight photoelectricconversion elements arranged in at least two columns and sharing afloating diffusion.
 11. The image sensor of claim 10, wherein for eachof the plurality of pixel groups, the at least eight photoelectricconversion elements included therein comprises a first pair ofphotoelectric conversion elements of a first spectral sensitivity, asecond pair of photoelectric conversion elements of a second spectralsensitivity, a third pair of photoelectric conversion elements of thesecond spectral sensitivity, and a fourth pair of photoelectricconversion elements of a third spectral sensitivity.
 12. The imagesensor of claim 11, wherein pixel signals are read out from theplurality of pixel groups such that, for a given pixel group, pixelsignals from paired photoelectric conversion elements are summed.
 13. Animaging apparatus, comprising: the image sensor of claim 10, and a lensunit that focuses incident light on the pixel unit.
 14. An image sensorcomprising: a pixel unit that has a plurality of pixel groups, each ofthe plurality of pixel groups including at least two photoelectricconversion elements that are arranged in a column direction and share afloating diffusion element; and wherein a first photoelectric conversionelement has a first exposure time and a second photoelectric conversionelement that is in a same row as the first photoelectric conversionelement and that is in a different pixel group than the firstphotoelectric conversion element has a second exposure time which isdifferent from the first exposure time, and wherein a thirdphotoelectric conversion element that is in the same row as the firstand second photoelectric conversion elements has a third exposure timethat is different from the first and second exposure times.
 15. Animaging apparatus, comprising: the image sensor of claim 14, and a lensunit that focuses incident light on the pixel unit.
 16. An image sensorcomprising: a pixel unit that has a plurality of pixel groups, each ofthe plurality of pixel groups including at least two photoelectricconversion elements that are arranged in a column direction and share afloating diffusion element; and wherein a first photoelectric conversionelement has a first exposure time and a second photoelectric conversionelement that is in a same row as the first photoelectric conversionelement and that is in a different pixel group than the firstphotoelectric conversion element has a second exposure time which isdifferent from the first exposure time, wherein the pixel unit includesa plurality of photoelectric conversion elements arranged in rows andcolumns, including the first and second photoelectric conversionelements, and exposure times of the plurality of photoelectricconversion elements are set such that each row includes somephotoelectric conversion elements that have the first exposure time andsome photoelectric conversion elements that have the second exposuretime, and wherein the pixel unit includes a plurality of photoelectricconversion elements arranged in rows and columns, including the firstand second photoelectric conversion elements, each row has at leastthree exposure control wirings corresponding thereto, and each of theexposure control wirings is connected to some of the photoelectricconversion elements in the corresponding row and controls exposure timesfor those photoelectric conversion elements to which it is connected.17. The image sensor of claim 16, wherein a first type of row ofphotoelectric conversion elements consists of photoelectric conversionelements of a first spectral sensitivity and photoelectric conversionelements of a second spectral sensitivity, a second type of row ofphotoelectric conversion elements consists of photoelectric conversionelements of the first spectral sensitivity and photoelectric conversionelements of a third spectral sensitivity, the rows of photoelectricconversion elements are arranged so as to alternate between the firsttype of row and the second type of row in a column direction.
 18. Theimage sensor of claim 17, wherein, for the first type of row, a firstone of the exposure control wirings that correspond to the row isconnected to photoelectric conversion elements of only the firstspectral sensitivity and the other ones of the exposure control wiringsthat correspond to the row are connected to photoelectric conversionelements of the second spectral sensitivity, for the second type of row,a first one of the exposure control wirings that correspond to the rowis connected to photoelectric conversion elements of only the firstspectral sensitivity and the other ones of the exposure control wiringsthat correspond to the row are connected to photoelectric conversionelements of the third spectral sensitivity, and for each of the rows,the exposure control wiring that is connected to the photoelectricconversion elements of only the first spectral sensitivity is disposedbetween the other exposure control wirings that correspond to the row.19. The image sensor of claim 16, wherein, for each of the rows, theexposure control wiring that is connected to the most photoelectricconversion elements out of the exposure control wirings that correspondto the row is disposed between the other exposure control wirings thatcorrespond to the row.
 20. An imaging apparatus, comprising: the imagesensor of claim 16, and a lens unit that focuses incident light on thepixel unit.